热等静压Cr_3C_2/Ni_3Al复合材料的微观组织及相组成  

Microstructure and phases constitution of Cr_3C_2/Ni_3Al composites prepared by hot isostatic pressing (HIP)

作　　者：傅丽华[1,2] 韩伟[1] 李长海[3] 董超芳[2] 赵琳[1] 田志凌[1] 

机构地区：[1]钢铁研究总院,北京100081 [2]北京科技大学材料科学与工程学院,北京100083 [3]查尔姆斯理工大学材料与制造技术学院,瑞典哥德堡se41296

出　　处：《钢铁研究学报》2016年第12期52-58,共7页Journal of Iron and Steel Research

基　　金：国家国际科技合作专项资助项目(2015DFA50970;2012DFG51670);清华大学摩擦学国家重点实验室开放基金资助项目(SKLTKF14B11)

摘　　要：采用热等静压技术(HIP)在1160℃、100MPa条件下制备出Cr_3C_2/Ni_3Al复合材料,研究了Cr_3C_2/Ni_3Al复合材料的微观组织和相组成。结果表明,Cr_3C_2初始颗粒首先溶解成Cr和C原子,并往基体中扩散;冷却过程中,溶解的Cr和C原子转化为稳定的Cr_7C_3结构;由于Ni_3Al合金中的Fe易与C形成稳定碳化物,促使Fe原子从基体中往Cr_7C_3结构中发生上坡扩散,并取代Cr_7C_3结构中的部分Cr原子形成M_7C_3(M为Cr、Fe,余同)结构的扩散相。当Cr_3C_2初始颗粒较大时,在高温过程中,Cr_3C_2颗粒未能全部溶解,而未溶解的Cr_3C_2颗粒芯部在冷却过程中仍保持为Cr_3C_2结构。该条件下制备的Cr_3C_2/Ni_3Al复合材料主要由Cr_3C_2硬芯相、M_7C_3扩散相和γ′-Ni_3Al基材相组成,其中Cr_3C_2硬芯相和γ′-Ni_3Al基材相通过M_7C_3扩散相形成良好的扩散连接;该结构的复合材料磨损后表面Cr_3C_2颗粒末发生剥落且沟槽在铬碳化物处发生中断,表现出良好的耐磨性。The Cr3 C2/Ni3 Al composite materials were prepared by hot isostatic pressing （HIP）at 1 160℃ and 100 MPa. Microstructure and phases constitution of the composite materials were investigated.The results indicate that the original Cr3 C2 particle firstly dissolves into Cr and C atoms and then diffuses into the matrix.During the cooling process,the dissolved Cr and C atoms transformed into a stable Cr7 C3 structure.Also,an uphill diffusion phe-nomenon is observed for Fe element from the matrix to the Cr7 C3 carbide phase,which is attributed to the easy formation of stable carbides of Fe element in Ni3 Al alloy with C element.And,the Fe atoms substitute a part of Cr atoms in Cr7 C3 carbides and form a diffusion phase with M7 C3 （M for Cr,Fe）structure.When the original Cr3 C2 par-ticles are large,it cannot be completely dissolved during the high temperature period.The undissolved core of Cr3 C2 particles still remain the Cr3 C2 structure after the cooling process.The Cr3 C2/Ni3 Al composite materials are composed of Cr3 C2 hard core phase,M7 C3 diffusion phase andγ′-Ni3 Al matrix material phase.The Cr3 C2 hard core phase and theγ′-Ni3 Al matrix created a good diffusion bonding by the formed M7 C3 diffusion phase.There-fore,the Cr3 C2 particle on the worn surface does not peel off and the groove is interrupted around the chromium carbides during the wear test,resulting in significantly improved wear resistance of Cr3 C2/Ni3 Al composites.

关 键 词：热等静压 Cr3 C2/Ni3 AL复合材料 微观组织 相组成 M7 C3 

分 类 号：TB33[一般工业技术—材料科学与工程]